Integrated condition based maintenance and spare parts supply with incoming quality control and inspection errors

The advancement in communications and sensing technology is facilitating the spread of condition-based maintenance (CBM) in the industry. It is of high importance to include the impact of spare parts quality, lead-time, and the inspection errors of the incoming quality control on maintenance cost and system's availability. We propose a new maintenance model capturing the effects of the previous characteristics in addition to replacement cost, holding cost, and shortage cost. In a case study, our model is optimized by determining the degradation threshold at which a spare part is ordered. We show that a proper inspection of spare parts pays back up to 22% in maintenance cost savings as the quality of the spare parts deteriorates. The vendor lead-time, the offered spare part price, and the mean degradation per time unit have a significant impact on the optimal maintenance cost. Finally, the costly detection processes of defective items installed in the system, due to inspection error, have a limited cost reduction.